This invention relates to a hydraulic cylinder that is easily disassembled. More particularly, the hydraulic cylinder has an easily removable piston that simplifies maintenance and repair work on the cylinder.
The invention provides a construction for a hydraulic cylinder which eliminates the need for providing a removable cylinder head for the cylinder or barrel of the unit. This eliminates the difficulty of providing a pressure seal between the head and barrel of the cylinder. It also greatly reduces the cost of fabrication and assembly for the hydraulic cylinder.
Unitary or integrally formed hydraulic cylinders have been used for years. These cylinders present difficulties relating to the means by which the piston is mounted in the cylinder and the means by which the piston is retained in the cylinder during normal operation. Such unitary cylinders are frequently cast in one piece or formed of welded construction such that the piston is inserted into the completed cylinder through a bore which slideably and sealingly engages a piston in normal use. However, there have been difficulties providing a satisfactory means for retaining the piston in the cylinder and also allowing for removal of the piston when desired.
Various methods have been proposed including the use of snap rings, threaded extensions and the like which must be introduced into the cylinder and coupled to the piston. In many of these systems the cylinder must be machined or cast of a particular configuration to accommodate the ingress and internal positioning of the retaining member for subsequent coupling to the piston within the cylinder. The cost of machining and fabricating such a unit is usually very high. Other prior art cylinders require introduction of a tool into a special tool access opening in the cylinder to remove the retaining member from the piston to permit the piston to be withdrawn from the cylinder.
It is an object of the invention to provide a construction for a hydraulic cylinder which provides for easy removal of the piston from the cylinder.
It is a further object of the invention to provide a hydraulic cylinder where the piston can be removed from the cylinder without using special tools or access ports in the cylinder.
Other objects and advantages of the invention will be clear from the following description of the invention.